1. Field of the Invention
This invention relates to a surface treatment method, an etching method, and a method for manufacturing an electronic device.
2. Background Art
In the manufacturing of highly integrated semiconductor devices in recent years, the surface of a substrate or other workpiece needs to be highly cleaned. To this end, reaction products (deposits) deposited on the workpiece surface and the trench sidewall need to be completely removed.
As a technique for removing reaction products (deposits) deposited on the workpiece surface and the trench sidewall, wet cleaning such as RCA cleaning is known. The wet cleaning allows a relatively simple apparatus to remove the reaction products (deposits), and hence is widely used in the manufacturing of electronic devices such as semiconductor devices. However, the wet cleaning has a problem of high running cost and environmental load because it uses a large amount of chemicals.
For this reason, dry cleaning such as HF (hydrogen fluoride) vapor cleaning, and a combined technique of wet cleaning and dry cleaning are proposed (see JP-A H5-090239(Kokai) (1993)).
Here, after the completion of the etching process, the workpiece is transported to a cleaning apparatus and subjected to the above wet cleaning or dry cleaning in the cleaning apparatus. In this case, if a long time elapses from the etching process to the cleaning process, corrosion due to reaction products may occur and decrease the product yield.